There are a lot of factors that can lead to these multiple conditions which occur over many years. This results in the gradual loss of hearing both progressively and symmetrically.

Doctor’s and hearing professionals use the term presbycusis when referring to age-related hearing loss. It is the cumulated result caused by aging to hearing. This condition can even grow worse due to other factors which include exposure to loud noise, harmful medication and other forms of disease conditions.

In the early stage of presbycusis, high-frequency hearing loss is experienced. Gradually, even the ability to hear low-frequency noise is lost. As the condition worsens, speech discrimination and auditory processing become difficult. Presbycusis can be experienced very early in life and it continues to progress as you age. Even very young adults sometimes begin to experience a hearing loss of high-frequency sounds of above 15 to 16 kHz.  Estimated 30 to 35 percent of adult aged between 65 to 75 experience some degree of hearing loss in the speech frequencies. In adults above 75, the prevalence increases to about 40 to 50 percent. Conversely, this condition affects one out of three people aged 65 to 75 and one out of two in people aged over 75 years.

Presbycusis is accompanied by tinnitus most of the time. Presbycusis is more predominant in males than in females. Hearing loss has been identified as the major cause of tinnitus. In a study carried out on a hearing loss, it was found that about 11% of people with presbycusis are also experiencing tinnitus.

When it comes to old age disease rating, presbycusis has being rated as the second most common illness after arthritis.

Some of the factors that cause presbycusis

It is important to understand that hearing loss is uncertainly connected with aging. A study of industrial and non-industrial societies shows that people retain their hearing ability even at very advanced ages.  According to results obtained from the Framingham cohort, only 10 percent of the inconsistency of hearing with age can be associated and described as being related to functional degeneration as a result of aging.

In other words, other factors are more prevailing when discussing age-related hearing loss.

There are 3 distinctive components of the aging process. These include Functional degeneration, extrinsic damage (nosocusis) and intrinsic damage (sociocusis).  These factors are superimposed on a genetic substrate. In some cases, they are surpassed by the general vulnerability to disease and other medical disorders that are caused by advancement in age.

Nosocusis  

These are factors that are associated with gradual hearing loss that do not have any connection with exposure to loud noise. They are also distinct from pure presbycusis and they include the following factors:

  • Hereditary factors: this can contribute to how early the cochlea ages as well as its vulnerability to damage by harmful drugs.
  • Atherosclerosis: This is a health condition characterized by the reduced supply of blood and oxygen to the cochlea. When this occurs, the sensitive hair nerves in the ear that need constant replenishment of blood and oxygen begin to die off gradually.
  • The consumption of saturated fat: this can lead to an acceleration of atherosclerosis causing the hearing loss to progress even faster.
  • Smoking: this has a lot of health effects which includes damage to the ear. One way in which smoking affects your hearing is by heightening the effect of atherosclerosis and increases the progression of presbycusis.
  • Diabetes: Diabetic patients are more vulnerable to presbycusis. This is because diabetes leads to a reduced supply of blood to the cochlea. When the supply of blood to the cochlea is reduced, the hair nerves in the ear are left in danger of gradually getting damaged.
  • The effect of hypertension: Just like diabetes, hypertension can also affect the supply of blood and oxygen to the cochlea which also results in gradual damage of hearing over an extended period.
  • Ototoxic medication: ototoxic medications are harmful to the nerves involved in hearing and maintaining balance. There are drugs out there that clearly states ototoxic as one of its adverse effects. These kinds of drugs can hasten the progression of presbycusis. It is therefore advisable to stay off such medications.
  • Oxidative stress: presbycusis has also been associated with oxidative stress.
  • General inflammatory conditions: other disease conditions can lead to gradual hearing loss.

Sociocusis

This is a form of presbycusis that is associated with continuous exposure to loud noise. These kinds of noises are often background noises that are unrelated to working environments. This includes continuous noise from traffic, noises from the use of home appliances such as vacuum cleaners, blenders, personal sound systems, television, etc. when these sounds accumulate over years, it can lead to conditions that are related to pure presbycusis.

Symptoms of presbycusis

There are quite a number of symptoms associated with presbycusis. These symptoms are classified into primary and secondary symptoms.

Primary symptoms of presbycusis

  • The gradual degeneration of sound and speech which is characterized by dull speech and sounds. Speech and sound can be stifled or weakened making it difficult to communicate freely.
  • The need for higher volumes on appliances such as televisions, sound systems, and radios becomes relatively increased.
  • Using the phone becomes a bit more difficult.
  • Identifying the direction of sound also becomes difficult.
  • There is an increased difficulty of speech understanding, this is most noticeable in women and children.
  • Cocktail party experience. This refers to the condition whereby it becomes difficult to differentiate between a conversation and a background noise.

Secondary symptoms of presbycusis

  • Hyperacusis: the increased sensitivity to specific volumes and sound frequencies as a result of “recruitment”.
  • Tinnitus: This is very common and characterized by buzzing sound, hissing, ringing and even whistling sound when there is no external sound present.

These secondary symptoms usually occur in persons over the age of 50. Nonetheless, hearing deterioration has been discovered to start very early in life. For some, it is as early as 18 years. According to the ISO standard 7029, there are expected threshold changes that occur strictly as a result of age. This is for the carefully screened populace which excludes those with one form of ear problem or the other and those exposed to loud noise.

Despite the age-related consequences, even young adults can lose the hearing ability of higher frequencies that will only become reasonably noticeable as they grow older.

The six types of Presbycusis

Some changes occur during presbycusis. These changes are often microscopic with the common being the degeneration of the cochlea and the giant stereocillary. Four pathological phenotypes have been identified to be associated with presbycusis. These are:

  • Sensory presbycusis: this is characterized by the degeneration of the spiral organ which is the organ responsible for hearing. The spiral organ is located inside the scala media and it contains hair cells with stereocilia. This stereocilium extends to the tectorial membrane. The outer hair of the organ is very important as they are responsible for the amplification of sound. They are also very sensitive to both internal and external factors and once damaged, they do not regenerate. This leads to a gradual loss of hearing sensitivity. This also leads to the subnormal sounds heard in regards to the tonotopic spectrum caused by the damaged hairs.

This kind of hearing loss usually begins at the base of the cochlea and gradually progresses to the inner tip of the cochlea. Sensory presbycusis leads to a sharp drop in the ear perceives high-frequency sounds. In this situation, the ability of the individual to understand speech remains moderately good. The process of degeneration starts around mid-life of later at an advanced age.

  • Neural presbycusis: this kind of presbycusis is characterized by the degeneration of the spiral cochlear. It is the atrophy of the nerve cells. That affected areas are usually the cochlea and auditory pathways that lead to the brain. According to studies, about 2,100 out of 35,500 becomes damaged after every decade of life. when 50 percent or more of the cochlea neurons are lost, this is referred to as neural presbycusis. The loss is usually something that is gradually and begins early in life. in some cases, this loss can be due to genetic factors. The effect of this loss is hardly noticeable until the person reaches an advanced age. People suffering from neural presbycusis have an excessive decrease in their perception of speech when likened to their level of hearing loss.
  • Metabolic/ Strial presbycusis: An atrophy of the Stria Vascularis leads to metabolic or stria presbycusis. The stria vascularis is responsible for the supply of blood to the inner ear. It is also responsible for the maintenance of the chemical and bioelectric balance of the cochlea. When atrophy of the stria occurs, it leads to a hearing loss that is represented by a flat curve. This means that the different frequencies are affected in equal amounts (high and low frequencies). Since the entire cochlea is affected by this kind of hearing loss, it does not affect speech discrimination. This process is most likely to occur within the last two to three decades of life. the progress of this kind of presbycusis is slow and can also be hereditary.

 

  • Mechanical/ Cochlea conductive presbycusis: this is as a result of the stiffening of the basilar membrane. This, in turn, affects its movement. Nonetheless, this type of pathology remains unverified as one of the contributing factors of presbycusis. The basilar membrane provides support to the organ of Corti in the ear and is responsible for aiding the translation of sound vibrations into electrical signals. Mechanical/ cochlea conductive hearing loss associates with a progressively slanting high-frequency sensorineural hearing loss. The progress remains reasonably slow and the level of speech discrimination is equal to the individual’s level of hearing loss.

There are two other types. While these types are relatively uncommon, it is also important that we understand them as well.

  • Indeterminate presbycusis: this term is used to refer to the situation in which presbycusis does not show any of the above characteristics. According to studies, about 25 percent of all the presbycusis cases do not show any of the above-mentioned characteristics of the 4 kinds of presbycusis.
  • Mixed presbycusis: when there is a combination of two or more of the presbycusis mentioned above, this can be referred to as mixed presbycusis.

While presbycusis occurs in different forms and can be categorized, it is still, however, difficult to differentiate one type from the other. However, we also understand that presbycusis no matter which one it remains the common cause of hearing loss in advanced adults.

Diagnosis of presbycusis

Hearing loss is classified according to severity. Doctors classify hearing loss into three different categories which are mild, moderate and severe (profound).

The diagnosis of presbycusis is done with the use of pure-tone audiometry to conduct the hearing threshold at different Hz. The doctor starts at 250 and continues to double it. That is, 250, 500, 1000, 2000, 4000 and 8000 Hz. This is the traditional method for classifying the degree of hearing loss in specific ears.

The standard hearing threshold is placed at 25 dB sensitivity. However, recent research has proposed 15 dB as the right threshold claiming that 25 dB is too high. When we talk of mild hearing loss, we refer to hearing loss within 25-45 dB. Moderate presbycusis falls within the range of 45-65 dB while the severe hearing loss falls within 65-85 dB. Doctors in some cases will use the profound hearing loss to refer to hearing loss that goes above 85 dB threshold.

When tinnitus occurs in only one ear, the healthcare professional should conduct further tests and etiologies. When the presence of a pulse-synchronous whoosh sound is heard, additional imaging may be required to eliminate the vascular disorder.

There are various kinds of tests that are used to identify and monitor the progress of presbycusis. Let us look at some of them below.

1.    Otoscopy

This is the examination of the external auditory canal and the tympanic membrane. This kind of test is usually carried out by an audiologist, a medical doctor or an otolaryngologist. The major tool for this examination is an otoscope. An otoscope is a visual instrument that is inserted into the ear to help the doctor ascertain the condition of the middle ear through the transparent membrane known as the tympanic membrane.

2.    Tympanometry

In this kind of ear test, the doctor, audiologist or otolaryngologist examines the tympanic membrane and the function of the middle ear using an instrument known as the tympanometer. This device is a sound wave/ air pressure device that is inserted into the ear canal. The result obtained from this test is referred to as tympanogram and it shows the ear canal volume, the compliances of the middle ear pressure and the eardrum. A normal middle ear function which is referred to as type A tympanogram with a hearing loss can be a sign of presbycusis. Type B and Type C tympanogram show an aberration inside the auditory canal. This can have an increased effect on a person's hearing ability.

3.    Laboratory test

A laboratory test may require a blood or other sera test. Here, the doctor checks for inflammatory markers such as those that are responsible for autoinflammatory diseases.

4.    Audiometry

This kind of test is usually conducted at the ENT unit by a professional. Here, the use of pure tone audiometry and speech recognition are employed. This test aims to ascertain the level and the nature of the hearing loss. Audiometry is also used to differentiate presbycusis from other kinds of hearing loss. The use of otoacoustic emission and evoked response testing may be employed for the testing of audio neuropathy.

Audiometry remains one of the best ways to identify the existence of a sensorineural hearing loss. This identifies significant hearing loss without the “air-bone gap” which is one of the major characteristics of a conductive hearing issue. In simple terms, when we talk of conduction, we refer to bone conduction. During audiometry, people suffering from cochlea shortfall do not pass the otoacoustic emission test. On the other hand, patients with 8th cranial nerve (vestibulocochlear nerve) shortfalls will not pass the auditory brainstem response examination.

5.    Magnetic resonance imaging (MRI)

While this kind of test is not commonly used except in rare cases, it can also be one of the methods of diagnosis for presbycusis. This test can be used to determine vascular anomalies, structural problems such as enlarged mastoids and tumor in the ear. Nonetheless, using an MRI or other kind of test will not directly identify or even measure age-related hearing loss. This is one reason why MRI is not often used as a form of diagnosis.

Treatment of presbycusis

It is important to understand that presbycusis which is primarily sensorineural does not have a cure and also cannot be prevented. Therefore, the treatment for presbycusis falls within the categories of management, surgical and pharmacology. So far, there are no specifically approved pharmaceutical treatments recommended for presbycusis. Treatment methods for presbycusis include the following;

The use of cochlea implants

When a hearing loss is identified as severe/profound, a cochlea implant is used to correct the problem. The cochlea implant is a small electronic device that is designed to replace the damaged cochlea in the inner ear. This process involves inserting electrodes through the round window of the cochlea which goes into the fluid-filled scala tympani. This process aims to stimulate the peripheral axons of the primary auditory neurons. These neurons, therefore, send information to the brain through the auditory nerves.

 

The use of Middle ear implants

The middle ear implant is a surgically implanted hearing aid. They are implanted directly into the middle ear and they aim to directly vibrate the ossicles. These kinds of implants are very discreet and suitable for those who don’t love the idea of wearing a hearing aid.

The use of hearing aids and aural rehabilitation to manage presbycusis

The hearing aid: Hearing aids are a very useful device for the management of presbycusis and other forms of hearing loss. Over the past decades, a lot of efforts have been put into the research and improvement of hearing aids. Thanks to these researches, one can now tune the hearing aid a specific frequency and hearing loss range.

Aural rehabilitation: this is very important for persons whose speech patterns have been relatively affected by presbycusis. Some of the important tips you need to understand during aural rehabilitation include the following:

  • Ensure that the room is properly lighted
  • Face the affected person squarely
  • Ensure you use a noise-free area and utilize contextual tools to recover comprehension.
  • Use proper pronunciation to improve speech.

Conclusion

Over the years, hearing loss has been seen as a disease of the elderly. However, it is important to understand that while the signs become relatively noticeable at old age, the process starts as early as 18 years. As one advance in age, the deterioration continues.

There are also some factors that can hasten the effect of presbycusis over the years which includes diet, environmental factors and even drug habits.

Damaged ear cells like we looked at it are not replaceable and do not regenerate when they are damaged. This is why it is important to take anything about your ear health very seriously. It is therefore important to go for hearing check once you notice abnormal signs in the ear. Your health professional may refer you to an audiologist or an ENT hearing professional.

During a hearing test, the audiologist or healthcare professional might request your previous health records as well as ask about your private life which includes habits, working and living environment, lifestyle and preferences. This will enable him to understand more about your conditions, help you make adjustments where necessary to the various habits that may be further affecting your hearing.

The doctor, ENT professional or the audiologist is in the best position to recommend treatment for hearing loss. OTC medication is strongly discouraged for patients experiencing a hearing loss.